{"id":941,"date":"2021-02-18T20:48:54","date_gmt":"2021-02-18T12:48:54","guid":{"rendered":"https:\/\/www.52dixiaowo.com\/java\/?p=941"},"modified":"2021-02-18T20:48:55","modified_gmt":"2021-02-18T12:48:55","slug":"predicate-%e5%87%bd%e6%95%b0%e5%bc%8f%e6%8e%a5%e5%8f%a3","status":"publish","type":"post","link":"https:\/\/www.52dixiaowo.com\/java\/post-941.html","title":{"rendered":"Predicate \u51fd\u6570\u5f0f\u63a5\u53e3"},"content":{"rendered":"\n

\u6b64\u63a5\u53e3\u662f\u4e00\u4e2a\u6d4b\u8bd5\u578b\u63a5\u53e3<\/p>\n\n\n\n

1.\u5bfc\u5305<\/h5>\n\n\n\n
import java.util.function.Predicate;<\/code><\/pre>\n\n\n\n
2.\u65b9\u6cd5<\/h5>\n\n\n\n
1.\u6b64\u63a5\u53e3\u5305\u542b\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5 boolean test(T t)<\/p>\n\n\n\n
\u6b64\u63a5\u53e3\u4e5f\u662f\u4e00\u4e2a\u6cdb\u578b\u7c7b\uff0c\u5373 Predicate<T>\uff0c\u4f7f\u7528\u6cdb\u578b\u4f20\u9012\u4e00\u4e2a\u6570\u636e\u7c7b\u578b<\/p>\n\n\n\n
import java.util.function.Predicate;\npublic class Demo {\r\n    \/*\r\n        \u5b9a\u4e49\u4e00\u4e2a\u65b9\u6cd5\r\n        \u53c2\u6570\u4f20\u9012\u4e00\u4e2aString\u7c7b\u578b\u7684\u5b57\u7b26\u4e32\r\n        \u4f20\u9012\u4e00\u4e2aPredicate\u63a5\u53e3,\u6cdb\u578b\u4f7f\u7528String\r\n        \u4f7f\u7528Predicate\u4e2d\u7684\u65b9\u6cd5test\u5bf9\u5b57\u7b26\u4e32\u8fdb\u884c\u5224\u65ad,\u5e76\u628a\u5224\u65ad\u7684\u7ed3\u679c\u8fd4\u56de\r\n     *\/\r\n    public static boolean checkString(String s, Predicate<String> pre){\r\n        return  pre.test(s);\r\n    }\r\n\n    public static void main(String[] args) {\r\n        \/\/\u5b9a\u4e49\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n        String s = \"abcdef\";\r\n        \/\/\u8c03\u7528checkString\u65b9\u6cd5\u5bf9\u5b57\u7b26\u4e32\u8fdb\u884c\u6821\u9a8c,\u53c2\u6570\u4f20\u9012\u5b57\u7b26\u4e32\u548cLambda\u8868\u8fbe\u5f0f\r\n        boolean b = checkString(s,str->str.length()>5);\r\n        System.out.println(b);\r\n    }\r\n}<\/code><\/pre>\n\n\n\n
2.\u63a5\u53e3\u7684\u9ed8\u8ba4\u65b9\u6cd5  and <\/p>\n\n\n\n
import java.util.function.Predicate;\npublic class Demo {\r\n    \/*\r\n        \u5b9a\u4e49\u4e00\u4e2a\u65b9\u6cd5,\u65b9\u6cd5\u7684\u53c2\u6570,\u4f20\u9012\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n        \u4f20\u9012\u4e24\u4e2aPredicate\u63a5\u53e3\r\n            \u4e00\u4e2a\u7528\u4e8e\u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5\r\n            \u4e00\u4e2a\u7528\u4e8e\u5224\u65ad\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5305\u542ba\r\n            \u4e24\u4e2a\u6761\u4ef6\u5fc5\u987b\u540c\u65f6\u6ee1\u8db3\r\n     *\/\r\n    public static boolean checkString(String s, Predicate<String> pre1,Predicate<String> pre2){\r\n        return pre1.and(pre2).test(s);\/\/\u7b49\u4ef7\u4e8ereturn pre1.test(s) && pre2.test(s);\r\n    }\r\n\r\n    public static void main(String[] args) {\r\n        \/\/\u5b9a\u4e49\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n        String s = \"abcdef\";\r\n        \/\/\u8c03\u7528checkString\u65b9\u6cd5,\u53c2\u6570\u4f20\u9012\u5b57\u7b26\u4e32\u548c\u4e24\u4e2aLambda\u8868\u8fbe\u5f0f, \u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5,\u5224\u65ad\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5305\u542ba\r\n        boolean b = checkString(s,(String str)->str.length()>5,(String str)->str.contains(\"a\"));\r\n        System.out.println(b);\r\n    }\r\n}<\/code><\/pre>\n\n\n\n
3.\u63a5\u53e3\u7684\u9ed8\u8ba4\u65b9\u6cd5 or<\/p>\n\n\n\n
import java.util.function.Predicate;\npublic class Demo{\r\n    \/*\r\n            \u5b9a\u4e49\u4e00\u4e2a\u65b9\u6cd5,\u65b9\u6cd5\u7684\u53c2\u6570,\u4f20\u9012\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n            \u4f20\u9012\u4e24\u4e2aPredicate\u63a5\u53e3\r\n                \u4e00\u4e2a\u7528\u4e8e\u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5\r\n                \u4e00\u4e2a\u7528\u4e8e\u5224\u65ad\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5305\u542ba\r\n                \u6ee1\u8db3\u4e00\u4e2a\u6761\u4ef6\u5373\u53ef\r\n         *\/\r\n    public static boolean checkString(String s, Predicate<String> pre1, Predicate<String> pre2){\r\n        return  pre1.or(pre2).test(s);\/\/\u7b49\u4ef7\u4e8ereturn pre1.test(s) || pre2.test(s);\r\n    }\r\n\r\n    public static void main(String[] args) {\r\n        \/\/\u5b9a\u4e49\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n        String s = \"bc\";\r\n        \/\/\u8c03\u7528checkString\u65b9\u6cd5,\u53c2\u6570\u4f20\u9012\u5b57\u7b26\u4e32\u548c\u4e24\u4e2aLambda\u8868\u8fbe\u5f0f,\u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5,\u5224\u65ad\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5305\u542ba\r\n        boolean b = checkString(s,(String str)->str.length()>5,(String str)->str.contains(\"a\"));\r\n        System.out.println(b);\r\n    }\r\n}<\/code><\/pre>\n\n\n\n
4.\u63a5\u53e3\u4e2d\u7684 negate \uff08\u53d6\u53cd\uff09<\/p>\n\n\n\n
import java.util.function.Predicate;\npublic class Demo {\r\n    \/*\r\n           \u5b9a\u4e49\u4e00\u4e2a\u65b9\u6cd5,\u65b9\u6cd5\u7684\u53c2\u6570,\u4f20\u9012\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n           \u4f7f\u7528Predicate\u63a5\u53e3\u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5\r\n    *\/\r\n    public static boolean checkString(String s, Predicate<String> pre){\r\n        \/\/return !pre.test(s);\r\n        return  pre.negate().test(s);\/\/\u7b49\u6548\u4e8ereturn !pre.test(s);\r\n    }\r\n\r\n    public static void main(String[] args) {\r\n        \/\/\u5b9a\u4e49\u4e00\u4e2a\u5b57\u7b26\u4e32\r\n        String s = \"abc\";\r\n        \/\/\u8c03\u7528checkString\u65b9\u6cd5,\u53c2\u6570\u4f20\u9012\u5b57\u7b26\u4e32\u548cLambda\u8868\u8fbe\u5f0f,\u5224\u65ad\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u662f\u5426\u5927\u4e8e5,\u5e76\u8fd4\u56de\u7ed3\u679c\r\n        boolean b = checkString(s,(String str)->str.length()>5);\r\n        System.out.println(b);\r\n    }\r\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
\u6b64\u63a5\u53e3\u662f\u4e00\u4e2a\u6d4b\u8bd5\u578b\u63a5\u53e3 1.\u5bfc\u5305 2.\u65b9\u6cd5 1.\u6b64\u63a5\u53e3\u5305\u542b\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5 boolean test(T t) \u6b64… \u7ee7\u7eed\u9605\u8bfb Predicate \u51fd\u6570\u5f0f\u63a5\u53e3<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[28],"tags":[],"_links":{"self":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts\/941"}],"collection":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/comments?post=941"}],"version-history":[{"count":0,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts\/941\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/media?parent=941"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/categories?post=941"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/tags?post=941"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}